Evaluation of Percutaneous Intramyocardial Septal Pulsed Field Ablation in a Rabbit Model: Safety, Efficacy, and Feasibility

Background Percutaneous intramyocardial (PIM) septal pulsed field ablation (SPFA) represents an innovative technique for the management of hypertrophic obstructive cardiomyopathy. However, the paucity of pertinent animal models has impeded comprehensive investigation. This study aimed to assess the safety, efficacy, and feasibility of PIM‐SPFA, as well as to examine the pathological alterations in the interventricular septum (IVS) postablation, utilizing a healthy rabbit model. Objective This study aims to evaluate the efficacy, safety, and feasibility of PIM‐SPFA in an animal model. Method In this study, percutaneous apical septal puncture under transthoracic echocardiography (TTE) guidance was employed to deliver a PFA catheter for treatment. The laboratory rabbits were allocated into a control group and an experimental group. Laboratory rabbits did not have hypertrophic obstructive cardiomyopathy. The experimental group was further subdivided into four cohorts based on varying PFA energies: 600, 800, 1000, and 1200 V, with the control group receiving 0 V. The experimental animals were monitored using electrocardiography, hemodynamic assessments, and cardiac enzymology. Histological analyses, encompassing triphenyl tetrazolium chloride (TTC) staining and Masson’s trichrome staining, were conducted 6 weeks postoperatively. Results The maximum diameter of PFA‐induced myocardial damage exhibited a positive correlation with increasing electric field strength (0 V: 0.49 ± 0.06 mm; 600 V: 1.52 ± 0.11 mm; 800 V: 2.78 ± 0.29 mm; 1000 V: 4.09 ± 0.49 mm; 1200 V: 5.03 ± 0.81 mm; F = 51.11, p < 0.01). Postoperative monitoring at the 6‐week mark demonstrated a significant reduction in the peak left ventricular outflow tract (LVOT) velocity (1000 V: 1.15 ± 0.21 to 0.75 ± 0.13 m/s; 1200 V: 1.12 ± 0.16 to 0.70 ± 0.13 m/s, p < 0.05). Intra‐SPFA therapy did not precipitate severe malignant arrhythmias, and no atrioventricular block (AVB) was observed on perioperative electrocardiograms. Histological analysis revealed that the injury site was characterized primarily by myocardial necrosis, with preservation of microvessels and nerve fibers and was predominantly fibrotic in nature, with an absence of significant inflammatory cell infiltration. Conclusions A novel therapeutic approach for septal reduction therapy (SRT) has been introduced, integrating PIM septal techniques with PFA. This combined method, referred to as PIMSPFA, has demonstrated preliminary safety and efficacy in current animal studies. Notably, it effectively ablates myocardial tissue with precision while mitigating the risk of long‐term conduction system damage.